Suction roll for paper web or sheet in a paper converting machine

Abstract

A suction roll (1) of a paper web or sheet (5) comprising a tubular body (10) arranged to rotate about a longitudinal rotation axis (101) and provided with an outer lateral surface (11) and an inner lateral surface (12) communicating with each other by a plurality of suction holes (3) by the action of air. Furthermore, the roll (1) comprises a suction chamber (20) connected by the action of air to vacuum generating means for generating a predetermined degree of vacuum. Furthermore, vacuum distribution means (50) are provided to selectively pneumatically communicate the suction chamber (20) with at least one row of suction holes (3) of the plurality of suction holes (3) at determined angular positions of the tubular body (10) and to cause the treated paper sheet or web (5) to be sucked and adhere at a corresponding portion of the outer lateral surface (11) arranged between a capture point and a release point (P1, P2) having the determined angular positions. Furthermore, displacement means (70) are provided to move the vacuum distribution means (50) so as to vary the angular position of the capture point (P1) and / or of the release point (P2) of the paper web or sheet and, therefore, to anticipate or delay the capture instant (ta) and / or the release instant (tr) in which the paper web or sheet adheres to or leaves the outer lateral surface (11) of the suction roll (1).

Description

Technical Field

[0001] This invention relates to the technical field of paper conversion and similar products, and more specifically, to a machine for interlacing folding of paper webs or sheets, the machine being equipped with at least one suction roller, specifically a cutting roller or a folding or interlacing roller, the at least one suction roller being provided with suction holes connected to a vacuum system to cause the paper sheet or web to adhere to its surface. Background Technology

[0002] As is well known, many machines are used in the paper industry, such as winding and cross-folding machines, which are equipped with systems for adhering the treated paper web or sheet to the surface of the rolls in a defined working step, thereby guiding the paper or web along the desired path through the machine.

[0003] Specifically, these systems are used to perform very important paper cutting operations, or to transfer the paper very quickly from one roller to another, or to provide the final folding of the paper in order to obtain a folded or staggered folded product.

[0004] The system that causes the aforementioned adhesion can be provided with a mechanical clamp or a pneumatic suction system.

[0005] In the case of a pneumatic system, a device for generating a defined vacuum level is provided, typically a vacuum pump, which is connected to the interior of the suction roller by air. More precisely, the surface of the suction roller is provided with a defined number of rows of suction holes distributed on the roller surface, so that the treated web or sheet of paper adheres only to the defined portion. Typically, the suction roller provides three or four rows of suction holes close to each other, one row positioned at 120° or 90° relative to the other, and is connected to the vacuum generating device by air at the defined angular position of the suction roller, thereby causing the treated web or sheet of paper to adhere to the defined portion of the suction roller surface.

[0006] For example, EP1457444 describes a known type of suction roller. Specifically, the suction roller of EP1457444 can be a forward roller or a folding roller, comprising a tubular body provided with the aforementioned multiple rows of holes, for example, four rows of holes arranged at 90° to each other, and configured to rotate about a longitudinal axis under operating conditions. Furthermore, the suction roller is provided with a second tubular body coaxially mounted within the aforementioned tubular body. Specifically, the inner tubular body is air-actuated to a device for generating a determined vacuum level, and furthermore, two sealing members are provided, extending longitudinally between the aforementioned tubular bodies relative to the holes or on opposite sides of each hole. In this way, the inner tubular body, the inner surface of the outer tubular body, and the two longitudinal sealing members define a suction chamber at a defined location on the suction roller. Therefore, the paper web or sheet is drawn into the suction chamber at a first point having a first predetermined angular position, where the longitudinal suction holes are positioned within the suction chamber by rotation of the outer tubular body, or more precisely, immediately downstream of the sealing member. Then, the paper web or sheet is released at a second point having a second predetermined angular position, where the longitudinal suction holes are positioned outside the suction chamber by rotation of the outer tubular body, or more precisely, immediately downstream of the second sealing member. Thus, the paper web or sheet is held on the surface portion of the suction roller located between the first and second points for the aforementioned cutting, folding, or forward movement along the machine.

[0007] However, the solution described in EP1457444 and other similar prior art solutions have some drawbacks.

[0008] Specifically, the forward speed of the processed paper web or sheet along a machine in which suction rollers as described in EP1457444 and other similar suction rollers are installed cannot overcome a predetermined threshold, typically about 150 m / min to 200 m / min, which is imposed by the construction and functional limitations of the determined machine components.

[0009] The aforementioned speed values ​​for the paper's forward movement along the machine, along with the path to be followed, are also used to design the suction rollers, specifically to position the sealing member at a predetermined angular location. Conversely, if the aforementioned speed values ​​for designing the suction rollers are not adhered to during machine operation, various types of problems may occur. Specifically, if the aforementioned threshold is exceeded, due to the paper's inertia, even after the second angular position, i.e., at the surface portion positioned downstream of the second sealing member, the processed web or sheet of paper may still adhere to the surface of the suction rollers. This causes the paper web or sheet to move inaccurately through different sections of the machine, and in addition to inevitably impairing the quality of the final product—specifically, forming undesirable folds—it can also cause the paper to become clogged, requiring the machine to be stopped to remove the clogged paper, thus resulting in lost time and production capacity.

[0010] For example, when the suction roller described in EP1457444 is used as a folding roller to obtain staggered folded products, the stack of staggered folded paper sheets is not accurately formed when the speed exceeds the specified limit, and in some cases, the machine may become clogged.

[0011] Therefore, in order to avoid the aforementioned functional defects and the loss of quality of the final product, it is necessary to operate at a predetermined speed; it is impossible to operate beyond that speed.

[0012] A similar drawback in existing machines is that, when paper webs or sheets are to be processed, they have a different paper weight than the weight on which the aforementioned suction rollers are designed. In fact, because paper with a higher weight exhibits greater inertia relative to paper with a lower weight, if paper webs or sheets with a weight exceeding a predetermined limit are processed, the processed paper webs or sheets will still adhere to the suction rollers beyond a predetermined release point, and generally cover a greater distance than that caused by the rollers' suction, resulting in the aforementioned functional drawbacks and product quality loss. Therefore, existing machines equipped with suction rollers are rigid because they must accept mass arrangements to operate paper webs or sheets with different paper weights. Summary of the Invention

[0013] Therefore, the object of the present invention is to provide a suction roller, specifically a cutting roller or a folding or staggered folding roller, which can overcome the aforementioned disadvantages of the prior art suction rollers.

[0014] Specifically, the object of the present invention is to provide a suction roller that can prevent wrinkles or “creases” on the processed paper sheet, and thus ensure a high-quality final product, regardless of the feed speed of the web, and specifically wherein the feed speed is higher than the threshold disclosed above.

[0015] The present invention also aims to provide a folding or staggered folding unit equipped with a suction roller of this type, which is capable of folding or staggering paper webs or sheets at high speeds without compromising the quality of the final product.

[0016] Another object of the present invention is to provide a method for drawing paper webs or sheets in a paper converter, which has the aforementioned advantages over prior art methods.

[0017] These and other objectives are achieved by a folding or staggering folding roller, according to the invention, feeding a paper web or sheet or similar product in the forward direction in a paper converter, the suction roller comprising:

[0018] - A tubular body configured to rotate about a longitudinal axis of rotation in a predetermined direction of rotation, the tubular body having an outer lateral surface and an inner lateral surface, the outer lateral surface and the inner lateral surface being connected to each other by air action through a plurality of suction holes organized according to a plurality of longitudinal rows;

[0019] - A suction chamber, which is defined within the suction roller and connected to a vacuum generating device by air action, the vacuum generating device being configured to generate a predetermined vacuum degree;

[0020] - A vacuum dispensing device configured to selectively pneumatically communicate the suction chamber at a defined angular position of the tubular body with at least one row of suction holes among the plurality of suction holes, and configured to cause the treated sheet or web to be suctioned, and configured to adhere to a corresponding portion of the outer lateral surface of the suction roller, the corresponding portion being arranged between a capture point (P1) and a release point (P2) having a defined angular position;

[0021] The main feature of the method is that, in addition, a displacement device is provided, which is configured to move the vacuum distribution device, thereby changing the angular position of the capture point (P1) and / or the release point (P2) of the paper web or sheet, and thus advancing or delaying the capture moment (ta) and / or release moment (tr) at which the paper web or sheet adheres to or leaves the outer lateral surface of the suction roller.

[0022] Other technical features of the present invention are defined in the embodiments of the present invention.

[0023] According to another aspect of the present invention, a method for feeding paper webs or sheets in a paper converter, the method comprising the following steps:

[0024] - The suction roller draws paper webs, sheets, or similar products from the outer lateral surface of the suction roller, the suction roller comprising:

[0025] - A tubular body configured to rotate about a longitudinal axis of rotation in a predetermined direction of rotation, the tubular body having an outer lateral surface and an inner lateral surface, the outer lateral surface and the inner lateral surface being connected to each other by air action through a plurality of suction holes organized according to a plurality of longitudinal rows;

[0026] - A suction chamber, which is defined within the suction roller and connected to a vacuum generating device by air action, the vacuum generating device being configured to generate a predetermined vacuum degree;

[0027] - A vacuum dispensing device configured to selectively pneumatically communicate the suction chamber at a defined angular position of the tubular body with at least one row of suction holes among the plurality of suction holes, and configured to cause the treated sheet or web to be suctioned, and configured to adhere to a corresponding portion of the outer lateral surface of the suction roller, the corresponding portion being arranged between a capture point (P1) and a release point (P2) having a defined angular position;

[0028] Furthermore, a displacement step is provided to move the vacuum distribution device, thereby changing the angular position of the capture point (P1) and / or the release point (P2) of the paper web or sheet, and thus advancing or delaying the capture moment (ta) and / or release moment (tr) at which the paper web or sheet adheres to or leaves the outer lateral surface of the suction roller. Attached Figure Description

[0029] The invention will now be illustrated with reference to the accompanying drawings by way of the following description of exemplary embodiments thereof, which are exemplary and not restrictive, wherein:

[0030] - Figure 1 A schematic side front view of a first embodiment of the suction roller according to the present invention is shown;

[0031] - Figure 2 and Figure 3 A schematic cross-sectional view of a first embodiment of the suction roller according to the invention is shown, illustrating the moment of capturing the paper web or sheet and the moment of releasing the paper web or sheet.

[0032] - Figure 4 and Figure 5 A side front view and a transverse cross-section of the first functional mode of the suction roller according to the present invention are schematically shown respectively;

[0033] - Figure 6 It shows Figure 5 An enlarged view of a portion schematically illustrates some aspects of the first functional mode of the suction roller according to the invention;

[0034] - Figure 7 and Figure 8 A side front view and a transverse cross-section of the second functional mode of the suction roller according to the present invention are schematically shown respectively;

[0035] - Figure 9 It shows Figure 8 An enlarged view of a portion schematically illustrates some aspects of the second functional mode of the suction roller according to the invention;

[0036] - Figure 10 The invention is schematically illustrated for use in Figure 1 A longitudinal cross-sectional view of an alternative embodiment of the suction roller;

[0037] - Figure 11 schematically shown Figure 10 A side front view of an alternative embodiment of the suction roller;

[0038] - Figure 12 and Figure 13 They are shown respectively Figure 10 and Figure 11 The illustrated embodiments of the rollers are shown in a side front view and a transverse cross section of the first functional mode for the left roller and the right roller.

[0039] - Figure 14 and Figure 15 They are shown respectively Figure 10 and Figure 11 The illustrated embodiments of the rollers are shown in a side front view and a transverse cross section of the second functional mode for the left roller and the right roller.

[0040] - Figure 16 and Figure 18 A transverse cross-sectional view of another possible alternative embodiment of the suction roller according to the invention is shown;

[0041] - Figure 17 It shows Figure 16 A magnified view of a portion of it to highlight some of its features;

[0042] - Figure 19 An illustration of the invention for use Figure 18 A side front view of another alternative embodiment of the suction roller;

[0043] - Figures 20 to 22 A side front view schematically illustrates some possible embodiments of a paper converter equipped with a suction roller according to the present invention. Detailed Implementation

[0044] like Figures 1 to 3 The suction roller 1, schematically shown in the diagram, feeding a paper web or sheet 5 or similar product in a paper converter along the forward direction 15, comprises a tubular body 10 configured to rotate about a longitudinal axis of rotation 101 in a predetermined direction of rotation 110, for example, clockwise. Figure 2 The situation is the same. More precisely, the tubular body 10 of the suction roller 1 is provided with an outer lateral surface 11 and an inner lateral surface 12 that are connected to each other through a plurality of suction holes 3.

[0045] Specifically, the suction holes 3 of the suction roller 1 can be organized according to multiple suction groups 30, such as two, three, or four suction groups 30, which are arranged at predetermined angular positions on the suction roller 1, for example, at 180°, 120°, or 90° relative to each other. Typically, the angular position of the suction group 30 depends on the number of paper sheets 5 that can be arranged adjacently on the outer lateral surface 11 of the suction roller 1. The arc between the suction group 30 and the next suction group is equal to the length of the processed paper sheet 5. Therefore, depending on the diameter of the suction roller 1, there can be two, three, four, or even more suction groups 30. For example, if there are five suction groups 30 on the suction roller 1, the angular distance between the suction groups 30 will be 72°. In the example described below, the suction roller 1 provides three suction groups 30, each of which includes two longitudinal rows of suction holes in the suction holes 3 close to each other. Furthermore, the suction roller 1 is provided with a suction chamber 20 arranged within the aforementioned tubular body 10 and is connected by air to a device for generating a predetermined vacuum, specifically a suction device, such as a vacuum pump. For simplicity, this suction device is not shown in the figures, but it is a type known to those skilled in the art. Additionally, a vacuum distribution device 50 is provided, configured to selectively pneumatically communicate the suction chamber 20 with at least one row of suction holes among the aforementioned plurality of suction holes 3 at a predetermined angular position on the tubular body 10. In this manner, it is well known that the treated paper sheet or web is suctioned and adheres only to a defined portion of the outer lateral surface 11 of the suction roller 1, which includes a capture point P1 and a release point P2 at the defined angular position, specifically relative to a predetermined reference system (Xo, Yo, Zo). According to the present invention, a displacement device 70 is provided, which is configured to move the aforementioned vacuum distribution device 50, thereby changing at least the angular position of the release point P2, specifically the angular position relative to a predetermined angular position relative to the aforementioned predetermined reference system (Xo, Yo, Zo). The displacement device 70 is operated by a main control unit, such as a PLC, industrial PC, or equivalent control unit, which is not shown in the figures for simplicity. The main control unit can be connected to the operator via an interface panel or HMI (Human Machine Interface), through which the operator can command and / or adjust the machine 100.

[0046] In this way, the moment ta in which the paper web or paper sheet adheres to the aforementioned outer lateral surface 11 of the suction roller 1 can be advanced or delayed, and / or the moment tr in which the paper web or paper sheet 5 leaves the aforementioned outer lateral surface 11 of the suction roller 1 can be advanced or delayed.

[0047] Specifically, the aforementioned displacement device 70 may be configured to move the aforementioned vacuum distribution device 50 according to at least one predetermined operating parameter of the machine 100, wherein the suction roller 1 is installed within the machine. For example, the aforementioned predetermined operating parameter may be the forward speed of the paper web or sheet along the machine 100.

[0048] In this case, specifically, if the forward speed v of the paper web or sheet is greater than a predetermined reference value v*, the displacement device 70 will be arranged to move the vacuum distribution device 50, thereby advancing the moment tr in which the paper web or sheet is released from the suction roller 1. Specifically, in this case, the displacement device 70 can be configured to rotate the aforementioned vacuum distribution device 50 in a direction opposite to the aforementioned rotation direction 110 of the suction roller 1 about the longitudinal rotation axis 101. Figures 4 to 6 ).

[0049] Conversely, if the machine 100 operates at a slower paper feed speed relative to the aforementioned reference value v*, the displacement device 70 is arranged to move the aforementioned vacuum distribution device 50, thereby delaying the separation of the paper web or sheet from the reference condition. More precisely, in this case, the displacement device 70 will be arranged to rotate the aforementioned vacuum distribution device 50 in the same direction as the aforementioned rotation direction 110 of the suction roller 1 about the longitudinal rotation axis 101. Figures 7 to 9 ).

[0050] In a preferred configuration of the invention, the vacuum dispensing device 50 can be rotated according to at least one operating parameter (e.g., the paper feed speed). In this case, the main control unit operates the displacement device 70 to rotate the vacuum dispensing device 50 appropriately. The main control unit can operate the displacement device 70 according to a predetermined function or based on a real-time calculation algorithm, such as a self-learning algorithm or, generally speaking, an artificial intelligence algorithm.

[0051] In an alternative embodiment of the invention, the positions of the capture point P1 and / or release point P2 can be controlled, alternating the angular position of the vacuum dispensing device 50 between at least two predetermined positions. For example, the position of the capture point P1 may correspond to a slow paper feed speed, while the position of the release point P2 may correspond to a high paper speed. In this case, a speed threshold can be set; exceeding this threshold, the displacement device 70 is operated to move the vacuum dispensing device 50 from the position of the capture point P1 to the position of the release point P2, advancing or delaying the release of the paper web or sheet 5. The operation command for the displacement device 70 may be given directly by the main control unit 300 or by the operator through an interface device of, for example, an HMI (Human-Machine Interface). Another operating parameter of the machine 100 may be the thickness s, or generally, the paper weight of the processed paper web or sheet; depending on this operating parameter, the displacement device 70 may be arranged to move the vacuum dispensing device 50. Specifically, if the thickness of the paper is greater than a predetermined reference thickness s*, the displacement device 70 can be configured to move the vacuum distribution device 50, thereby advancing the time tr at which the paper web or sheet 5 is released from the suction roller 1, specifically relative to the release reference time tr*.

[0052] Specifically, in this case, the displacement device 70 can be arranged to rotate the vacuum distribution device 50 in a direction opposite to the rotation direction 110 of the tubular body 10 about the longitudinal rotation axis 101. Conversely, when the paper thickness is less than a predetermined reference thickness s*, the displacement device 70 is arranged to move the vacuum distribution device 50, thereby delaying the moment when the paper web or sheet is released from the suction roller 1. Specifically, in this case, the displacement device 70 can be arranged to rotate the vacuum distribution device 50 in a rotation direction consistent with the rotation direction of the tubular body 10 about the longitudinal rotation axis 101.

[0053] In this case, the machine 100 can be adjusted according to the product, i.e., according to the characteristics of the paper that must be processed. The displacement device 70 can operate in different ways depending on the type of paper or product to be processed, thus gaining a significant advantage in terms of setup time for the machine 100 during product changes. The capture point P1 and release point P2 of the specific product or paper can be optimized according to the specific movement of the displacement device 70 or the specific reference value of the paper speed v*.

[0054] In a preferred embodiment of the invention, during the operating conditions of the machine 100 (meaning during the rotation of the tubular body 10 about the aforementioned longitudinal axis of rotation 101), the aforementioned displacement device 70 can be configured to move, specifically, the rotating vacuum distribution device 50, specifically, to delay or advance the moment tr in which the paper web or sheet is caused to detach from the outer side surface 11. In this way, specifically, the vacuum distribution device 50 can be moved to gradually follow the increase or decrease in the forward speed of the paper web or sheet.

[0055] Specifically, in the first embodiment, the aforementioned vacuum distribution device 50 may include a fixed tubular body 25 coaxially mounted within the aforementioned tubular body 10. More specifically, the aforementioned fixed tubular body 25 is air-actuated to a device for generating a predetermined vacuum level and is provided with at least one orifice 26. More precisely, the vacuum distribution device 50 may further include a first sealing member 27a and a second sealing member 27b, which are integral with the fixed tubular body 25 on opposite sides relative to the orifice or each orifice 26 and longitudinally positioned to the tubular body 10. Specifically, the displacement device 70 may be configured to rotate the fixed tubular body 25 about the aforementioned longitudinal rotation axis 101.

[0056] More specifically, such as in Figure 10 As schematically shown, the aforementioned displacement device 70 can be arranged to engage and fix the tubular body 25 at at least one actuating portion 75, which is advantageously a portion that protrudes axially from the end of the tubular body 10.

[0057] Specifically, if the purpose is relative to the reference condition tr* ( Figure 6 (The dashed line in the diagram) The early release time tr, for example, because machine 100 operates at a paper feed speed higher than the reference speed, specifically to increase production capacity, or for a type of paper with a paper weight s less than the reference paper weight s*, the displacement device 70 can be arranged to rotate and fix the tubular body 25 in a direction opposite to the predetermined rotation direction 110 of the tubular body 10. In this way, in fact, as in... Figure 6 The diagram schematically shows that the release point P2, which releases a sheet or web of paper from the outer lateral surface 11 of the tubular body 10, moves upstream of the reference release point P2* in the rotation direction 110.

[0058] Conversely, if the purpose is to operate the machine at a slower speed than the reference speed v*, or to operate a type of paper with a paper weight higher than the reference paper weight s*, the displacement device 70 can be arranged to rotate and fix the tubular body 25 about the longitudinal axis of rotation 101 in a rotation direction consistent with the predetermined rotation direction 110 of the tubular body 10, thereby delaying the moment tr at which the paper web or sheet 5 is released relative to the reference release moment tr* (see reference tr). Figures 7 to 9 In this way, in fact, as in Figure 9 The diagram schematically shows a paper sheet or web being released from the outer lateral surface 11 of the tubular body 10 at a release point P2 that moves downstream of a reference release point P2*.

[0059] In an alternative embodiment of the invention, the positions of capture point P1 and / or release point P2 change with the speed of machine 100, timely advancing or delaying at least one moment between two moments ta and tr, during which the paper sheet 5 is held on and released from the outer lateral surface 11 of the suction roller 1, respectively. In this case, to advance or delay the two moments ta or tr, a predetermined speed v* is not considered, and this predetermined speed is instead calculated by the main control unit based on the speed of machine 100 to determine the positions of capture point P1 and / or release point P2, and the displacement device 70 is commanded directly or indirectly by an operator giving commands through an interface device (e.g., HMI).

[0060] As in Figures 10 to 15 It is illustrated schematically, and specifically in Figure 11 In this device, the displacement device 70 may include an actuation device 73. Specifically, the actuation device 73 may be an actuator, such as a pneumatic actuator, a mechanical actuator, or an electromechanical actuator. Preferably, the actuation device 73 may be an electric motor having a motor shaft (not visible in the figure) arranged to rotate about a rotation axis 173. The motor shaft may be arranged to mesh with a worm gear 71 that slides along a sliding direction 171. More precisely, the worm gear 71 is pivotally connected at a engagement portion 76 to an actuation portion 75, which is integral with the fixed tubular body 25.

[0061] Therefore, in order to rotate the fixed tubular body 25 in the first direction, specifically in a direction opposite to the rotation direction 110 of the tubular body 10, the motor is operated, thereby causing the motor shaft to rotate about the rotation axis 173 in the first rotation direction 172 (see...). Figure 12 In this way, as described above, release point P2, at Figure 13 In the case of capture point P1, it is located at an angular position upstream of the reference capture point. Therefore, relative to the reference case tr* (see also...) Figure 6 The release time tr is in advance.

[0062] Conversely, in order to rotate the fixed tubular body 25 in the second rotational direction, specifically in the direction of rotation 110 of the tubular body 10, the motor is operated, thereby causing the motor shaft to rotate about the rotation axis 173 in the second rotational direction 172' (see...). Figure 14 In this way, as described above, release point P2, at Figure 15 In the case of capture point P1, it is located at an angle downstream of the reference capture point. Therefore, relative to the reference case tr* (see also...) Figure 9 The release time tr is delayed.

[0063] In an alternative embodiment of the invention, the actuation device 73 may be a linear electric actuator, i.e., an electric motor whose shaft is slidable rather than rotating. In this way, the electric motor can be directly connected at the engagement portion 76 to the actuation portion 75, which is integral with the fixed tubular body 25.

[0064] Specifically, in the implementation scheme described above, and more specifically in Figure 2 , Figure 3 , Figure 5 , Figure 13 and Figure 15 In the illustrated embodiment, the suction chamber 20 is connected to the suction port 3 by air action via a vacuum distribution device 50, which is equipped with a first sealing member 27a and a second sealing member 27b, which are radially oriented and positioned on opposite sides relative to the port or each port 26. Specifically, there are no other elements between the first sealing member 27a and the second sealing member 27b that can close the suction port 3.

[0065] exist Figure 16 and Figure 17 In an alternative embodiment illustrated schematically, the aforementioned vacuum dispensing device 50 includes a fixed tubular body 25 coaxially mounted within a tubular body 10 and connected by air action to a device for generating a predetermined vacuum level. More specifically, the fixed tubular body 25 is provided with at least one hole 26 having a predetermined angular amplitude that specifically corresponds substantially to the length of the panel, i.e., substantially to half the length of the paper sheet 5 to be processed, or the portion of the path that the web or paper sheet 5 must cover on the roller.

[0066] In this configuration, the vacuum distribution device 50 includes a plurality of sealing members 27 integral with and longitudinally positioned to the tubular body 10. More specifically, each sealing member 27 is associated with at least one row of suction holes 3, which are arranged to connect the outer lateral surface 11 to a device for generating a predetermined vacuum level via holes 26 by air action. Furthermore, an annular sealing member 28 may be provided between the sealing members 27 associated with two different suction groups 30 and subsequent sealing members 27. In this configuration, the displacement device 70 is advantageously configured to rotate the fixed tubular body 25 about a longitudinal axis of rotation 101. More precisely, for example, as Figure 17As shown in the details, in order to advance the release time tr of the paper sheet or paper web 5 relative to the reference condition tr*, the fixed tubular body 25 can rotate in a direction opposite to the rotation direction 110 of the tubular body 10. In this way, the release point P2 is positioned to move in the rotation direction 110, located upstream of the angular position of the reference release point P2*, because the suction hole 3 leaves the web or paper sheet 5 earlier than the reference condition (schematically depicted with dashed lines in the figure).

[0067] exist Figure 18 The alternative embodiments illustrated schematically are similar to those described in the above reference. Figure 5 , Figure 8 , Figure 13 and Figure 15 As described in the illustrated embodiment, the first sealing member 27a and the second sealing member 27b are arranged to extend longitudinally into the tubular body 10 between the inner lateral surface 12 and the fixed tubular body 25. However, in this case, at least one sealing member, such as the second sealing member 27b, is mounted on a movable support 21 that is movable relative to the fixed tubular body 25, for example within a guide 22 formed on the outer periphery of the fixed tubular body 25. Therefore, in this case, the displacement device 70 can be configured to move the movable support 21, specifically to rotate it about the longitudinal axis of rotation 101.

[0068] In this way, only the position of the release point P2 can be changed, while the position of the capture point P1 can be a fixed position that coincides with the reference position P1*.

[0069] Alternatively, a first displacement device 70a and a second displacement device 70b may be provided, one configured to move the movable support 21, and the other configured to move the tubular body 25. Therefore, in this manner, the capture point P1 and the release point P2 can be changed independently of each other. Figure 19 ).

[0070] In an alternative embodiment of the invention not shown, the first sealing member 27a and the second sealing member 27b may be mounted on two supports that are movable independently of each other to adjust the capture point P1 and / or the release point P2, thereby keeping the fixed tubular body 25 fixed.

[0071] The aforementioned suction roller 1 can be used as a folding or staggered folding roller in a paper conversion machine.

[0072] Specifically, according to another aspect of the invention, as in Figure 20 As schematically shown, the folding or staggered folding unit 150 of machine 100 may include a first suction roller 1a and a second suction roller 1b, as referenced above. Figures 1 to 19As described. Specifically, the first suction roller 1a and the second suction roller 1b are configured to fold or stagger the paper web or sheet according to a predetermined fold or stagger fold configuration at a fold or stagger fold area 35 defined therebetween.

[0073] In a possible alternative embodiment of the invention, the displacement device 70 includes a linear, electric, electromechanical, or pneumatic actuator arranged to force the vacuum dispensing device 50 to rotate against a movable abutment member. In this way, changing the position of the movable abutment member adjusts the angular position of the vacuum dispensing device 50.

[0074] Advantageously, in addition to the first suction roller 1a and the second suction roller 1b, the folding or staggered folding unit 150 may include a first plurality of release fingers 40a and a second plurality of release fingers 40b, which are arranged to operate in phase with the first suction roller 1a and the second suction roller 1b, respectively, to operate the release of the corresponding paper web or sheet 5 from the outer lateral surfaces 11 of the corresponding tubular bodies 10a and 10b. Specifically, a first actuation group 80a and a second actuation group 80b may be provided, which are configured to cause the first plurality of release fingers 40a and the second plurality of release fingers 40b to oscillate back and forth from / towards the aforementioned folding or staggered folding region 35, respectively. Specifically, the first actuation group 80a and the second actuation group 80b may further be configured to delay or advance the oscillating motion of the first plurality of disengagement fingers 40a and the second plurality of disengagement fingers 40b, specifically relative to a predetermined reference oscillating motion, thereby delaying or advancing the time tr at which the first plurality of disengagement fingers 40a and the second plurality of disengagement fingers 40b are arranged preferably relative to a predetermined release reference time tr* at which the paper web or sheet 5 disengages from the first suction roller 1a and the second suction roller 1b.

[0075] Specifically, in Figure 20In the first embodiment schematically shown, the first actuation group 80a and the second actuation group 80b respectively include a first actuation group 91a and a second actuation group 91b, which are respectively provided with a first motor group 85a and a second motor group 85b. Advantageously, these are respectively operatively connected to a first motor shaft 86a and a second motor shaft 86b. More precisely, the first motor group 85a and the second motor group 85b are arranged to rotate the first motor shaft 86a and the second motor shaft 86b about corresponding rotation axes 185a and 185b. The first actuation group 80a and the second actuation group 80b may also respectively include a first oscillator device 90a and a second oscillator device 90b, specifically a first mechanical oscillator and a second mechanical oscillator, which are configured to convert rotational motion on the inlet axis into oscillating motion on the outlet axis, specifically according to mechanical cams 84a and 84b disposed in the first oscillator device 90a and the second oscillator device 90b. Oscillator devices are known to those skilled in the art and will not be described in detail herein. A first motor shaft 86a and a second motor shaft 86b are connectable to the inlets of the first oscillator device 90a and the second oscillator device 90b, while the outlet shafts are advantageously connected to a first transmission group 81a and a second transmission group 81b, which are arranged to transfer oscillating motion to the first plurality of disengagement fingers 40a and the second plurality of disengagement fingers 40b. In this way, phase is obtained between the disengagement fingers 40a, 40b and the rest of the machine 100, causing the first motor group 85a and the second motor group 85b to rotate at a defined speed. Generally, any kinematic mechanism, such as a crank-connecting rod mechanism, can be used to convert the rotational motion of the first motor group 85a and the second motor group 85b into the oscillating motion of the first transmission group 81a and the second transmission group 81b. Advantageously, the phase of the disengaged fingers 40a and 40b can be adjusted, i.e., the oscillating motion of the first motor group 85a and the second motor group 85b relative to other mechanical mechanisms of the machine 100 can be delayed or advanced, decelerating or accelerating within a necessary time. In other words, if the first motor group 85a and the second motor group 85b rotate at a reference speed vm* within a time interval ∆t*, then the motors 85a and 85b decelerate or accelerate, and then their speed returns to the reference speed vm*. In effect, within a defined time period, by increasing or decreasing the rotational speed of the first and second rotating shafts relative to a set speed, the oscillating motion of the first plurality of disengaged fingers 40a and the second plurality of disengaged fingers 40b is respectively advanced or delayed.

[0076] Also in Figure 21In an alternative embodiment schematically shown, the first actuation group 80a and the second actuation group 80b respectively include a first motor group 85a and a second motor group 85b, which are provided with a first motor shaft 86a and a second motor shaft 86b, which are arranged to rotate about corresponding rotation axes 185a and 185b. Similarly, in this case, a first transmission group 81a and a second transmission group 81b are provided, which are arranged to transmit the oscillating motion generated at the outlets of the first oscillator device 90a and the second oscillator device 90b to the first plurality of disengaged fingers 40a and the second plurality of disengaged fingers 40b, respectively. However, in this case, as referenced above… Figure 20 The difference lies in that the first oscillator device 90a and the second oscillator device 90b are advantageously associated with a first adjustment device 94a and a second adjustment device 94b, respectively, which are configured to adjust the phase of the first plurality of disengagement fingers 40a and the second plurality of disengagement fingers 40b with respect to the corresponding suction rollers. Specifically, the first adjustment device 94a and the second adjustment device 94b are arranged to advance or delay the moment tr at which the first plurality of disengagement fingers 40a and the second plurality of disengagement fingers 40b are arranged to strike the paper web or sheet 5 to disengage it from the corresponding folding or staggered folding rollers.

[0077] Advantageously, the first adjusting device 94a and the second adjusting device 94b respectively include a first phase shifter gearbox 95a and a second phase shifter gearbox 95b of a type known to those skilled in the art. More precisely, in this case, the first phase shifter gearbox 95a and the second phase shifter gearbox 95b are operatively connected to the first motor assembly 85a and the second motor assembly 85b respectively, for example, via a first transmission belt 87a, and to the actuation assembly via second transmission belts 88a and 88b. Advantageously, the actuation assembly includes a first actuation device and a second actuation device, which are operatively connected to the first phase shifter gearbox 95a and the second phase shifter gearbox 95b respectively via the first transmission belt 87a and the second transmission belt 87b.

[0078] More precisely, the first actuation group 91a and the second actuation group 91b are arranged to transmit rotational motion to the first oscillator device 90a and the second oscillator device 90b, which convert the rotational motion into the aforementioned oscillating motion, which is then transmitted to the first disengaged finger 40a and the plurality of disengaged fingers 40b. The first phase shifter gearbox 95a and the second phase shifter gearbox 95b are respectively equipped with a first electric motor 96a and a second electric motor 96b. These are arranged to regulate the rotational speed of the first actuation group 91a and the second actuation group 91b, regulating the rotational speed and direction of the first and second epicycloid gears respectively housed within the first and second phase shifter gearboxes 95a and 95b. The first electric motor 96a and the second electric motor 96b can generally remain stationary, thus not changing the phase of the disengaged fingers 40a and 40b relative to other parts of the machine 100, specifically the phase of the folding roller. When it is necessary to change the phase of the disengagement fingers 40a and 40b, the first electric motor 96a and the second electric motor 96b are operated to temporarily accelerate or decelerate, and the second conveyor belts 88a and 88b introduce a delay or advance in the timing tr of the disengagement of the paper web or sheet 5 from the first suction roller 1a and the second suction roller 1b.

[0079] exist Figure 22 In another embodiment, schematically shown, a third suction roller 1c and a fourth suction roller 1d are provided downstream of the first suction roller 1a and the second suction roller 1b. These third and fourth suction rollers are configured to cut the corresponding paper web into predetermined first and second sheets of predetermined length, respectively. According to the invention, the third suction roller 1c and the fourth suction roller 1d may also be provided with corresponding displacement devices 70c and 70d, which are configured according to the above reference... Figures 1 to 15 One of the described embodiments moves the corresponding vacuum distribution device 50, thereby delaying or advancing the release point P2 of the corresponding processed paper web or sheet, and in some cases, a capture point P1. In this case, the third suction roller 1c and the fourth suction roller 1d are equipped with blades that engage with the opposing blades to perform a complete or partial cut of the paper web. The adjustment of the capture point P1 and the release point P2 improves the transfer of the web or sheet 5 from one roller to another, for example, as... Figure 22 As shown, the suction roller 1c is connected to the first suction roller 1a or the suction roller 1d is connected to the second suction roller 1b.

[0080] The reference values ​​cited above can be calculated using different methods. For example, as those skilled in the art will know, the reference position P1* and the reference release point P2* can be positions related to a starting position or a zero point. Alternatively, the reference position P1* and the reference release point P2* can refer to positions specific to the machine, i.e., calculated considering a machine operating at a defined speed. The reference position P1* and the reference release point P2* correspond, respectively, to the moment ta* when the paper web or sheet 5 adheres to the aforementioned outer lateral surface 11 of the suction roller 1 and the moment tr* when the paper web or sheet 5 leaves the aforementioned outer lateral surface 11 of the suction roller 1. In practice, the positions of the capture point P1 and the release point P2 can be changed from the starting position or the zero position, thus changing the moments ta and tr, depending on at least one parameter. These parameters can be the machine speed, paper weight, or the type of product to be produced.

[0081] In another case, the reference value may refer to the current state conditions of the machine, that is, it may refer to, for example, the instantaneous operating speed of the machine. In this way, the advance or delay of time ta and tr refers to the operating conditions of the machine at the moment when the phase or capture point P1, release point P2, or disengagement from the fingers 40a, 40b is changed.

[0082] From a conceptual standpoint, the foregoing description of exemplary embodiments of the present invention so fully discloses the invention that others, by applying present knowledge, will be able to modify and / or adapt various applications of such embodiments without further research and without departing from the invention. Therefore, it should be understood that such adjustments and modifications must be considered equivalent to the specific embodiments. Consequently, apparatus and materials for achieving the different functions described herein may have different properties without departing from the scope of the invention. It should be understood that the wording or terminology used herein is for illustrative purposes and not for limitation.

Claims

1. A suction roller (1) for feeding a paper web or sheet (5) in a forward direction in a paper converter, the suction roller (1) comprising: - A tubular body (10) configured to rotate about a longitudinal axis of rotation (101) in a predetermined direction of rotation (110), the tubular body (10) having an outer lateral surface (11) and an inner lateral surface (12), the outer lateral surface and the inner lateral surface communicating with each other through a plurality of suction holes (3) organized according to a plurality of longitudinal rows; - Suction chamber (20), the suction chamber being defined within the suction roller (1) and connected by air to a vacuum generating device, the vacuum generating device being configured to generate a predetermined vacuum degree; - A vacuum distribution device (50) is configured to selectively pneumatically communicate the suction chamber (20) with at least one row of suction holes (3) at a defined angular position of the tubular body (10), and is configured to cause the treated paper sheet or web (5) to be suctioned and adhered to a corresponding portion of the outer lateral surface (11) of the suction roller (1), the corresponding portion being arranged between a capture point and a release point (P1, P2) having a defined angular position; The suction roller (1) is characterized by having a displacement device (70) configured to move the vacuum distribution device (50) to change the angular position of the capture point (P1) and / or the release point (P2) of the paper web or sheet, and thus advance or postpone the capture moment (ta) and / or release moment (tr) at which the paper web or sheet (5) adheres to or leaves the outer lateral surface (11) of the suction roller (1).

2. The suction roller (1) of the paper web or sheet according to claim 1, wherein the displacement device (70) is configured to move the vacuum distribution device (50) during the rotation of the tubular body (10) about the longitudinal axis of rotation (101), thereby gradually following the increase or decrease of the forward speed of the paper web or sheet.

3. The suction roller (1) for a paper web or sheet according to claim 1 or 2, wherein the vacuum distribution device (50) comprises a fixed tubular body (25) coaxially mounted within the tubular body (10), the fixed tubular body (25) being air-connected to the device for generating a predetermined vacuum degree, and the fixed tubular body being provided with at least one hole (26), and wherein the displacement device (70) is configured to rotate the fixed tubular body (25) about the longitudinal axis of rotation (101).

4. The suction roller (1) of the paper web or sheet according to claim 2, wherein the displacement device (70) is arranged to engage the fixed tubular body (25) at least at the engagement portion (75) that axially protrudes from the end of the tubular body (10).

5. The suction roller (1) of the paper web or paper sheet according to claim 2, wherein the displacement device (70) includes an actuation device (73).

6. The suction roller (1) for a paper web or sheet according to claim 5, wherein the actuating device (73) is an electric actuator or a pneumatic actuator or a combination thereof.

7. The suction roller (1) for a paper web or sheet according to claim 1, wherein the displacement device (70) includes a movable abutment member configured to adjust the position of the vacuum distribution device (50).

8. The suction roller (1) for a paper web or sheet according to claim 5, wherein the actuation device (73) is configured to operate based on commands given by an operator via an interface panel or human-machine interface.

9. The suction roller (1) for a paper web or sheet according to claim 5, wherein the actuation device (73) is configured to be operated by an electronic control unit (300) according to at least one of the following parameters: -Instantaneous operating speed of the suction roller (1); - The length of the paper sheet; - Paper weight.

10. The suction roller (1) of the paper web or sheet according to claim 9, wherein the electronic control unit (300) is configured to operate the actuation device (73) to move the vacuum distribution device (50) in a continuous or alternating manner between at least two predetermined positions.

11. The suction roller (1) for a paper web or sheet according to claim 3, wherein the vacuum dispensing device (50) comprises a first sealing member and a second sealing member (27a, 27b), the first sealing member and the second sealing member being integral with the fixed tubular body (25) on opposite sides relative to the hole or each hole (26), the first sealing member and the second sealing member (27a, 27b) being longitudinally positioned to the tubular body (10).

12. The suction roller (1) for a paper web or sheet according to any one of claims 1-2 and 4-10, wherein the vacuum distribution device (50) further comprises a plurality of sealing members (27, 28) integral with and longitudinally positioned to the tubular body (10), each of the plurality of sealing members (27, 28) being associated with at least one row of suction holes arranged to connect the outer lateral surface (11) to the device for generating a predetermined vacuum degree by air action.

13. The suction roller (1) for a paper web or sheet according to any one of claims 1-2 and 4-10, wherein the vacuum dispensing device (50) comprises a plurality of sealing members (27a, 27b) arranged longitudinally to the tubular body (10), the plurality of sealing members (27a, 27b) being positioned on at least one movable support (21) configured to move relative to the tubular body (10) and the fixed tubular body (25), and wherein the displacement device (70) is configured to cause rotation of the movable support (21) about the longitudinal axis of rotation (101).

14. The suction roller (1) for a paper web or sheet according to any one of claims 1-2 and 4-11, wherein the displacement device (70) is configured to rotate the fixed tubular body (25) about the longitudinal axis of rotation (101) in a rotation direction consistent with the predetermined rotation direction (110) of the tubular body (10) to delay the release time (tr) of the paper sheet or paper web relative to a reference release time (tr*), or to rotate in a direction opposite to the predetermined rotation direction (110) of the tubular body (10) to advance the release time (tr) of the paper sheet or paper web relative to the predetermined reference release time (tr*).

15. The suction roller (1) for a paper web or sheet according to any one of claims 1-2 and 4-11, characterized in that, The suction roller is a forward roller, which is configured to move the paper web or sheet in a predetermined forward direction in the paper converter.

16. The suction roller (1) for a paper web or sheet according to any one of claims 1-2 and 4-11, characterized in that, The suction roller is a cutting roller, which is configured to cut the paper web into multiple sheets of predefined length.

17. The suction roller (1) for paper webs or sheets according to any one of claims 1-2 and 4-11, characterized in that, The suction roller is a folding or staggered folding roller, which is configured to fold or stagger the paper web or sheet according to a predetermined folding or staggered folding configuration.

18. The suction roller (1) of a paper web or sheet according to any one of claims 1-2 and 4-11, wherein the multiple longitudinal rows of suction holes in the suction holes (3) are organized according to a plurality of suction groups (30), each of the plurality of suction groups comprising at least two longitudinal rows of suction holes in the suction holes (3) that are close to each other.

19. The suction roller (1) for a paper web or sheet according to any one of claims 1-2 and 4-11, wherein the multiple longitudinal rows of suction holes in the suction holes (3) are organized according to a plurality of suction groups (30), each of the plurality of suction groups comprising at least 3 longitudinal rows of suction holes in the suction holes (3) that are close to each other.

20. The suction roller (1) of the paper web or sheet according to claim 19, wherein the distance between two subsequent suction groups (30) of the plurality of suction groups is equal to the length of the processed paper sheet (5).

21. A folding unit for a paper web or sheet, said folding unit comprising: - A suction roller for a paper web or sheet according to any one of the preceding claims, wherein the suction roller includes a first suction roller and a second suction roller (1a, 1b), the first suction roller and the second suction roller (1a, 1b) being configured to fold or alternately fold the paper web or sheet according to a predetermined folding or alternate folding configuration at a folding or alternate folding area arranged between the first suction roller and the second suction roller (1a, 1b); - A first plurality of detachment fingers and a second plurality of detachment fingers (40a, 40b), the first plurality of detachment fingers and the second plurality of detachment fingers being configured to detach the paper web or sheet from the outer lateral surface (11) of the respective suction roller (1a, 1b); - A first actuation group and a second actuation group (80a, 80b), which are respectively configured to cause the first plurality of disengagement fingers and the second plurality of disengagement fingers (40a, 40b) to oscillate back and forth from / to the folded or staggered folded area (35), thereby causing the corresponding paper web or sheet to disengage from the first suction roller and the second suction roller (1a, 1b).

22. The folding unit for a paper web or sheet according to claim 21, wherein the first actuation group and the second actuation group (80a, 80b) further include a phase adjustment device (85) configured to introduce a delay or advance in the oscillating motion, thereby delaying or advancing the moment when the first plurality of disengagement fingers and the second plurality of disengagement fingers (40a, 40b) are arranged to strike the respective paper web or sheet to disengage the respective paper web or sheet from the respective suction roller.

23. A method for feeding paper webs or sheets into a paper converter, the method comprising the following steps: - The suction roller (1) draws paper webs or sheets (5) from the outer lateral surface (11) of the suction roller (1), the suction roller comprising: - A tubular body (10) configured to rotate about a longitudinal axis of rotation (101) in a predetermined direction of rotation (110), the tubular body (10) having the outer lateral surface (11) and an inner lateral surface (12), the outer lateral surface and the inner lateral surface being connected to each other by air action through a plurality of suction holes (3) organized according to a plurality of longitudinal rows; - Suction chamber (20), the suction chamber being defined within the suction roller (1) and connected by air to a vacuum generating device, the vacuum generating device being configured to generate a predetermined vacuum degree; - Vacuum dispensing device (50), which is configured to selectively pneumatically communicate the suction chamber (20) with at least one row of suction holes of the plurality of suction holes at a determined angular position of the tubular body (10), and is configured to cause the treated paper sheet or web (5) to be suctioned and adhered to the corresponding portion of the outer lateral surface (11) of the suction roller (1), the corresponding portion being arranged between a capture point and a release point (P1, P2) having a determined angular position; The method is characterized by an additional displacement step to move the vacuum distribution device, thereby changing the angular position of the capture point (P1) and / or the release point (P2) of the paper web or sheet, and thus advancing or delaying the capture time (ta) and / or release time (tr) of the paper web or sheet (5) adhering to or leaving the outer lateral surface (11) of the suction roller (1a, 1b).

24. The method according to claim 23, wherein the step of moving the vacuum dispensing device is arranged to change the angular position of the capture point (P1) and / or the release point (P2) of the paper web or sheet, and thus advance or postpone the capture time (ta) and / or the release time (tr) of the paper web or sheet (5) adhering to or leaving the outer lateral surface (11) of the suction roller (1a, 1b) relative to a predetermined reference angular position (P1*, P2*) corresponding to the capture point and the release point.

25. The method according to claim 23, wherein the displacement step of moving the vacuum distribution device (50) is performed by the actuating device (73).

26. The method of claim 25, the method comprising the command step of operating the actuator (73) via an interface panel or HMI (human-machine interface) or by commands given by an electronic control unit or PLC.

27. The method of claim 25, wherein an electronic control unit (300) is further provided, the electronic control unit being configured to operate the actuator (73) according to at least one of the following parameters: - The operating speed of the suction roller (1); - The length of the paper sheet; - Paper weight.

28. The method of claim 23, wherein the displacement step is adapted to move the vacuum distribution device (50) to change the angular position of the capture point (P1) and / or the release point (P2) of the paper web or sheet relative to the corresponding predetermined reference angular positions (P1*, P2*).

29. The method according to claim 28, wherein the reference angular position (P1*, P2*) refers to the predetermined start-up conditions or predetermined operating speed of the machine.

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